This invention relates to mine stoppings and to braces for such mine stoppings.
Mine stoppings are widely used in mine passageways to stop off the flow of air therethrough. A conventional metal stopping shown in U.S. Pat. No. 4,483,642 comprises a plurality of elongate extensible panels 7 extending vertically from the floor to the roof of the mine passageway and positioned in side-by-side relation across the passageway. (See FIG. 1 of the patent.)
Some mine passages can be quite large, e.g., 20 feet wide and 10 feet high and even as large as 60 feet wide and 35 feet high. Further, the pressure differential across a stopping can be very high. The high pressure differential and/or the large size of the mine passages that a stopping closes can subject the stopping to large forces which cause the stopping to bend or deflect. Satisfactory high pressure stoppings are disclosed in our co-pending U.S. patent application Ser. No. 10/061,146 filed Feb. 1, 2002, and in our U.S. Pat. No. 6,379,084, filed Dec. 17, 1999, both of which are incorporated herein by reference. This application is directed to improvements in stoppings and braces that are particularly advantageous for high pressure or large mine passageways.